暗针叶林不同林冠环境下华西箭竹(Fargesia nitida)分株种群的分布格局及分形特征研究

Spatial Distribution Patterns and Fractal Analysis of the Ramet Population of Fargesia nitida in Different Canopy Conditions of Sub-alpine Dark Coniferous Forests

以亚高山暗针叶林四种林冠环境的华西箭竹(Fargesia nitida)为对象,运用传统的格局研究方法和分形理论中的计盒维数法,对分株种群的分布格局进行了较系统的对比研究.结果显示:①不同的林冠环境下,华西箭竹分株种群的分布格局类型均为集群分布;②从林下至中林窗至大林窗,随着林冠郁闭度的减小,种群的聚集强度逐渐增大,计盒维数不断减小.表明华西箭竹克隆分株种群通过改变聚集强度和空间占据能力,对林冠环境的差异作出有效的响应,这些格局特征的变化有利于增强种群对异质生境中资源的获取和利用.

The clonal plant Fargesia nitida was surveyed in four different forest canopy conditions, inclu ding forest understory （FU）, moderate gap （MG）, large gap （LG） and forest edge wilderness（FEW）. Their distribution patterns were studied by using traditional methods of pattern research and the boxcounting dimension of fractal theory. The main results showed that all ramet populations of F. nitida dis P d ayed a pattern of clumping distribution and that the aggregation intensity increased and the box-counting mension decreased as canopy cover decreased （i. e. , from FU to MG to LG）. These results indicated that varieties of aggregation intensity and space-occupied capability of the clonal ramet populations of F. nitida were the effective response to the changed canopy conditions, which would enhance their ability to forage and utilize resources in heterogeneous habitats.